Zero the parameters if no results found

src/modb_users.c

@@ -111,6 +111,8 @@ int doUsersQuery(stored_conn *sconn, modb_ref *modb, where_builder *wb,
   // Zero row result
   if (qry_ret == 0) {
     freeColumns(col_data, n_cols);
+    *users = 0;
+    *n_users = 0;
     return 0;
   }